The Principal Investigator shall develop precise and rapid construction micromachining techniques and construct arrays of microelectrodes (MEAs) suitable for recording and stimulating neural tissue. These devices will be used specifically optimized for the use in the NIDCD mission areas of voice, speech, hearing, and balance. Novel fabrication techniques are required for precise and rapid construction of the MEAs. The MEAs will be supplied through coordination with the project officer to outside investigators supported by the NIDCD to perform animal studies for neural prosthesis development. These outside investigators will provide feedback on the electrode performance and request specific modifications for rearrangement and refinement of the electrode design. New MEA variations will then be constructed and distributed under this award in order to support cycles of electrode design, testing, and invention for neural prostheses. Initial tests with these devices will be restricted to acute and chronic animal studies, but electrode materials and fabrication techniques utilized to construct the MEAs must be suitable for eventual use in human studies.